1. Field of the Invention
The present invention relates to a connector and a method of connecting the connector, and particularly to a connector mounted on a printed wiring board and a method of connecting the connector.
2. Description of the Related Art
A connector has heretofore been used as means which connects electrical circuits formed respectively on printed wiring boards to each other. FIG. 4 is a perspective view showing a configuration of a conventional connector. A connector 100 includes a male plug 101 and a female socket (a receptacle) 103. The plug 101 is mounted on a surface of a printed wiring board 105, and the socket 103 is mounted on a surface of another printed wiring board 106. The plug 101 includes a plurality of contacts (connections) 102 used for electrical connection on each of outer side faces 101a of the plug 101. On the other hand, the socket 103 includes a plurality of contacts (connections) 104 used for the electrical connection on each of inner side faces 103a of the socket 103.
Next, descriptions will be given of a method of connecting the plug 101 to the socket 103. FIGS. 5A and 5B are cross-sectional views showing a procedure for connecting the plug 101 to the socket 103 of the connector 100 shown in FIG. 4. FIGS. 5A and 5B are cross-sectional views each taken along the line V-V in FIG. 4. Firstly, as shown in FIG. 5A, a male portion of the plug 101 is arranged so as to face a female portion of the socket 103. Next, as shown in FIG. 5B, the male portion of the plug 101 is inserted into the female portion of the socket 103. Accordingly, each of the contacts 102 and a corresponding one of the contacts 104 are connected to each other, i.e., come into contact with each other.
In a connector, it is generally required to reduce contact resistance between contacts on the plug and contacts on the socket for the purpose of reducing electrical losses in the connection between the plug and the socket. The gap between the contacts 102 and the contacts 104 in the connector 100 is made small enough to fulfill the requirement. However, in such a structure, when the plug 101 is inserted into the socket 103, an edge of any one of the contacts 102 may possibly abut on an edge of the corresponding one of the contacts 104. FIG. 6 is a cross-sectional view showing a problem associated with a conventional connector. When an edge of any one of the contacts 102 abuts on an edge of the corresponding one of the contacts 104 as described above, each of the contacts 104 of the socket 103 may possibly be crushed and thereby deformed, as indicated by reference numeral 111. In addition, even when an edge of each of the contacts 102 does not abut on an edge of the corresponding one of the contacts 104, each of the contacts 104 may possibly be deformed due to a friction applied to the surface of the contacts 102 and the surface of the contacts 104. Moreover, the contacts 104, if not deformed, may possibly be damaged. It should be noted that, not only the contacts 104 but also the contacts 102 of the plug 101 may possibly be crushed or deformed. For this reason, a conventional connector has a problem of reliability at the time of connection.
For the purpose of solving the above described problem, for example, a configuration as shown in FIG. 7 has been proposed. In the configuration shown in FIG. 7, upper portions of contacts 204 of a socket 203 are bent outward. The bending of the upper portions of the contacts 204 outward is a countermeasure taken to prevent an edge of each of the contacts 102 of the plug 101 from abutting on an edge of a corresponding one of the contacts 204 of the socket 203 when a plug 101 is inserted into the socket 203. In addition, in the related document 1 “Japanese Patent Application Laid-Open No. 2006-86083”, particularly, in FIGS. 3 and 4, a connector having a configuration similar to that of the connector shown in FIG. 7 is disclosed. In this configuration, edge portions of contacts of a socket (receptacle) are bent outward so as to prevent edge faces of contacts of the plug from abutting respectively on edge faces of the contacts of the socket.
However, in recent years, a connector mounted on a printed wiring board has been downsized more than ever as an electronic circuit on the printed wiring board has been miniaturized. For this reason, the surface area of each contact has necessarily been reduced. In order to suppress increase in contact resistance between contacts associated with the reduction in the surface area of each contact, it is required to further increase contact pressure between the contacts. For this reason, even in the connector shown in FIG. 7 and in the connector disclosed in the related document 1, a large friction may be generated between one of the contacts of the plug and the corresponding one of the contacts of the socket when the plug is inserted into the socket. Accordingly, a large mechanical stress may possibly be generated between the contact of the plug and the corresponding contact of the socket. As a result, the contacts may possibly be deformed or damaged. Moreover, in the configuration shown in FIG. 7 and the configuration disclosed in the related document 1, when the connector is repeatedly attached and detached, the contacts on both sides may be rubbed with each other and thus wear so that contact pressure may possibly be decreased. As a result, a problem may occur in which electrical connection loss is increased due to an increase in contact resistance. Moreover, in the configuration disclosed in the related document 1, the contacts on both sides are brought into contact with each other by means of the spring-like characteristic of the contacts. For this reason, contact pressure may possibly be reduced due to the passage of time.
Accordingly, a problem may occur in which electrical losses in the connection is increased due to increase in contact resistance. As described above, the aforementioned connectors have problems in assurance and reliability at the time of connection.